Embodiments of the present invention generally relate to cardiac stimulation devices and more particularly to systems and methods for determining pacing related parameters.
The normal electrical conduction of the heart allows electrical propagation to be transmitted from the sinoatrial node (SA) through both atria and forward to the atrioventricular node (AV). Normal physiology allows further propagation from the AV node to the ventricle or Purkinje Fibers and respective bundle branches and subdivisions. The SA and AV nodes stimulate the myocardium. Time ordered stimulation of the myocardium allows efficient contraction of all four chambers of the heart, thereby allowing selective blood perfusion through both the lungs and systemic circulation.
Implantable medical devices (IMDs) such as cardiac pacemakers or cardioverter defibrillators are used today for a variety of reasons to maintain an adequate heart rate. Recently, lead configurations have been introduced that include multiple electrodes located in, or proximate to, the left ventricle. IMDs are configured to monitor the electrical activity and pace in various chambers of a patient's heart. To do so, the IMD has a variety of operational parameters that can be adjusted to maintain desired cardiac function. Examples of such operational parameters are the delays between when combinations of electrodes deliver pacing pulses when no intrinsic event occurs, such as atrioventricular delay (hereinafter “AV delay”), right ventricle (RV) to left ventricle (LV) delay (hereinafter “RVLV delay” or “interventricular delay”) or LV to LV delay (hereinafter: LVLV delay” or “intraventricular delay”), and the like. The proper setting of these delays establishes and maintains the desired cardiac function, and results in an improved hemodynamic response.
Heretofore, IMDs have afforded the clinician certain parameters to program. However, clinician programmed settings may not result in the desired hemodynamic performance in all patients or under conditions for a particular patient.
A need remains for a process to search automatically for certain pacing related parameters, such as AV delay, RV to LV delay, and/or LV to LV delay.